• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.229-232
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• 2003

본 연구는 울산지역 지하수오염 저감기술의 개발에 필요한 대수층의 공간적 분포특성을 파악하는 데 목적이 있다. 울산 공업도시의 대수층에서 공간적 분포특성을 파악하기 위하여 시추조사가 많이 필요 하지만 비용 및 시간 관계상 어려움이 있기 때문에, 지질조사 보고서나 논문 등에서 지하수자료와 시추 자료를 획득하여 지구통계기법을 이용한 울산지역 대수층의 공간적 분포를 모사하였다. 그리고 인구가 밀집되어 있는 남구와 중구를 중심으로 대수층 단면 분포를 모사하였다. 이와 같은 분석결과는 표토층 하부경계부와 풍화대 하부경계부에서 유사한 분포심도로 나타났으며, 지하수 수위는 표토층 하부경계와 암반층 상부경계부인 풍화대에 분포하는 것으로 나타났다.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.457-465
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• 2013

We integrated and correlated datasets from surface and subsurface geophysics, drilling cores, and engineering geology to identify geological interfaces and characterize the joints and fracture zones within the rock mass. The regional geometry of a geologically weak zone was investigated via a fence projection of electrical resistivity data and a borehole image-processing system. Subsurface discontinuities and intensive fracture zones within the rock mass are delineated by cross-hole seismic tomography and analyses of dip directions in rose diagrams. The dynamic elastic modulus is studied in terms of the P-wave velocity and Poisson's ratio. Subsurface discontinuities, which are conventionally identified using the N value and from core samples, can now be identified from anomalous reflection coefficients (i.e., acoustic impedance contrast) calculated using a pair of well logs, comprising seismic velocity from suspension-PS logging and density from logging. Intensive fracture zones identified in the synthetic seismogram are matched to core loss zones in the drilling core data and to a high concentration of joints in the borehole imaging system. The upper boundaries of fracture zones are correlated to strongly negative amplitude in the synthetic trace, which is constructed by convolution of the optimal Ricker wavelet with a reflection coefficient. The standard deviations of dynamic elastic moduli are higher for fracture zones than for acompact rock mass, due to the wide range of velocities resulting from the large numbers of joints and fractures within the zone.

• Spatial Information Research
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• v.7 no.1
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• pp.147-153
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• 1999

Geological map and data are needed for land use planning, resources development, geological hazard prevention, environment protection and education, Since the nationwide geological database in Korea has not been constructed yet, there are many problems in using the geological map and data. There are many problems such a stratigraphy unestablishment, map conservation and edge matching in geological paper map. Therefore it is difficult to construct the geological map database, but the geological map database must be constructed as soon as possible as one of national thematic map. In this study, geological maps of pilot area such as Ansung geological map on a scale of 1:50,000, Busan on a scale of 1:250,000, Namchang on a scale of 1:25,000 and the whole Korean peninsula on a scale of 1:1,000,000 were designed and constructed to database using Geographic Information System(GIS). In addition the geological map management program was developed by GIS program. The digital geological maps were produced using the constructed geological database. The database could be of access through Internet World Wide Web(WWW) environment and be distributed in Compact Disk(CD).

• The Journal of Engineering Geology
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• v.19 no.1
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• pp.1-8
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• 2009

Geophysical surveys were conducted on an upper part of a natural slope located at Daejeon University. Electrical resistivity and seismic refraction measurements were carried out to obtain information on a weathered zone and internal structure at shallow depth, while AMT measurement a bed rock and geological structure at deep depth. With all the techniques applied, these results show a good correlation between electrical resistivity images and refraction velocity distributions for the characterization of a weathering and geological structure at depth. In particular, AMT survey seems to be the powerful tool for detecting a distribution of a bed rock with deep depth. The combined geophysical investigation produced a detailed image of a subsurface structure and improved well in the interpretation.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.143-155
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• 2022

In this study, the response acceleration amplification according to different conditions was analyzed by changing the boundary condition of the soil called LSB (Laminar Shear Box), which is placed on a 1 g shaking table for earthquake simulation experiments. Experiments were carried out with different boundary conditions by fixing both sides of the LSB, and two samples were tested by installing an accelerometer at the same location. In addition, using DEEPSOIL v7 program, a one-dimensional ground response analysis was performed to compare and analyze with the free field condition. As a result, it was confirmed that the acceleration was amplified as it went from the lower layer to the upper layer, and as a result of comparing it with the ground response analysis, it was confirmed that it appeared similar to the analysis under the free field condition. As a result of the SA (Spectrum acceleration) analysis, a result similar to that of the ground response analysis was obtained, and in the case of fixing, it was confirmed that the PSA (Peak Spectral Acceleration) was further amplified.

• The Journal of Engineering Geology
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• v.25 no.2
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• pp.237-250
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• 2015

Underground structures such as a tunnel have been considered as safer than structures on the ground during earthquake. However, severe damages of underground structures occurred at subway tunnel during 1995 Kobe Earthquake and such damages are gradually increased. In this study, a dynamic behavior of a cut and cover tunnel surrounded by weathered soils is investigated using Mohr-Coulomb Model. Parametric study was carried out for boundary conditions, tensile strength, and earthquake magnitudes. The results of numerical analyses in terms of ground deformations and stresses acting on the lining were quite dependent on the side boundary condition (free or fix conditions) and tensile strength of surrounding soils. The ground was deformed upward at the end of earthquake when the side boundary condition was fixed, whereas residual deformations were not predicted when it was free. When the tensile strength of a soil was set to the same as its cohesion, residual deformation was less than 1cm, regardless of side boundary conditions or input accelerations. In addition to that, stress conditions at the maximum deformation and end of earthquake were within an allowable range and considered as safe. Proper boundary conditions and material properties such as tensile strength are quite important because they may significantly impact on the results of dynamic analyses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3058-3068
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• 2014

This experimental research is aimed to apply a health promotion program based on Cox's interaction model to such college students as are on the brink of dyslipidemia, so as to investigate the effects of the program on the subjects' blood lipid indexes including total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoproteins (LDL). The subjects are 39 in all including the experimental group comprising 20 and the control group comprising 19. The analyses applied include descriptive statistics using SPSS WIN 18.0, $X^2$-test, independent t-test, and paired t-test. By means of nursing interventions which are an element of client-professional interaction, the following were offered including health information (exercise management, dietary management, health education), emotional support (sharing of experiences, encouragement, self expression), decision-making controlling (counselling by phone), and professional/ technical abilities; and blood lipid indexes were measured before and after the interventions. The results of this research found that TC, TG and LDL decreased significantly and HDL increased significantly in the experimental group, which indicates that the health promotion program was effective.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.522-529
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• 2014

Sea tangle (Laminaria japonica) is well known as having anti-diabetic and hypolipidemic effects in animals as well as in humans. In this study, we evaluated the effects of sea tangle-added patty on postprandial blood glucose and lipid profiles in borderline-hypercholesterolemic (cholesterol ${\geq}200$ mg/dL) adults. Eleven subjects voluntarily participated in the experiment, and each subject provided written consent. Experimental patty (E) was made by adding 2.25 g of sea tangle powder as a substitution to 1.125 g each of pork and chicken. In the first week, 200 g of Control patty (C) was provided to each subject, who had fasted more than 12 hours. In the second week, the same amount of E patty was supplied under the same conditions. Serum glucose levels increased significantly less at 30, 60, and 120 min after consumption of E patty compared to the levels at all time points after eating C patty. Thus, the change in the area under curve (${\Delta}AUC$) of serum glucose levels through 120 minutes was lower when consuming E patty compared to C patty. Although serum C-peptide concentrations were not significantly different at all time points between the two patties, the ${\Delta}AUC$ of serum C-peptide concentrations through 120 minutes was lower when consuming E patty compared to C patty. However, there were no differences in serum levels of triglyceride, total cholesterol, LDL-C, and HDL-C at 30, 60, 120, 180, and 240 min between the two patties. Further, each ${\Delta}AUC$ of these lipid levels through 240 minutes was not significantly different between the two patties. The results indicate that sea tangle-added patty may decrease postprandial plasma glucose concentrations and reduce insulin secretion, although it might not ameliorate serum lipid profiles in adults with borderline-hypercholesterolemia.

• Journal of the Korean earth science society
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• v.38 no.1
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• pp.80-90
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• 2017

To build tetrahedra mesh for FEM numerical analysis, Boundary Representation (B-Rep) model is required, which provides the efficient volume description of an object. In engineering, the parametric solid modeling method is used for building B-Rep model. However, a geological modeling generally adopts discrete modeling based on the triangulated surface, called a Sealed Geological Model, which defines geological domain by using geological interfaces such as horizons, faults, intrusives and modeling boundaries. Discrete B-Rep model is incompatible with mesh generation softwares in engineering because of discrepancies between discrete and parametric technique. In this research we have developed a converting program from Sealed Geological Model to Gmsh and COMSOL software. The developed program can convert complex geological model built by geomodeling software to user-friendly FEM software and it can be applied to geoscience simulation such as geothermal, mechanical rock simulation etc.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.235-258
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• 2022

We interpreted the evolutionary history of the southwestern part of the Pohang Basin, the largest Miocene basin in the southeastern part of the Korean Peninsula, based on the detailed geological mapping and analysis of the geological structures. The southwestern part of the Pohang Basin can be divided into the Bomun Domain in the west and Ocheon Domain in the east by an NNE-trending horst-in-graben. These two domains have different geometries and deformation histories. The Bomun Domain was rarely deformed after the incipient extension of the basin, whereas the Ocheon Domain is an area where continued and overlapped deformations occurred after the basin fill deposition. Therefore, the Bomun Domain provides critical information on the initial extension mode of the Pohang Basin. The subsidence of the Bomun Domain was led by the zigzag-shaped western border fault that consists of NNE-striking normal and NNW-striking dextral strike-slip fault segments. This border fault is connected to the Yeonil Tectonic Line (YTL), a regional dextral principal displacement zone and the westernmost limit of Miocene crustal deformation in SE Korea. Therefore, it is interpreted that the Pohang Basin was initially extended in WNW-ESE direction as a transtensional fault-termination basin resulting from the movement of NNE-striking normal and/or oblique-slip faults formed as right-stepover in the northern termination of the YTL activated since approximately 17-16.5 Ma. As a result, an NNE-trending asymmetric graben or half-graben exhibiting an westward deepening of basin depth was formed in the Bomun Domain. Afterward, crustal extension and deformation were migrated to the east, including the Ocheon Domain.